P-glycoprotein-like protein contributes to cadmium resistance in<Emphasis Type="Italic"> Euglena gracilis</Emphasis> |
| |
Authors: | Email author" target="_blank">M?Einicker-LamasEmail author M?M?Morales K?Miranda J?Garcia-Abreu A?J?F?Oliveira F?L?S?Silva M?M?Oliveira |
| |
Institution: | (1) Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, Brazil;(2) Departamento de Anatomia, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, Brazil |
| |
Abstract: | Selective pressures from polluted environments have led to the development of resistance systems in aquatic organisms. Using different techniques, this study examined a cadmium defense mechanism of the freshwater unicellular protozoa Euglena gracilis, and found it to be an efflux pump similar to the multidrug resistance P-glycoprotein. Cd2+-treated E. gracilis were able to extrude Rhodamine 123 at 21 °C, but not at 4 °C. Furthermore, verapamil, a P-glycoprotein modulator, partially blocked the efflux process (at 21 °C), and enhanced the Cd2+ toxic effects on these cells. Western immunoblots of cell lysates, using the anti-P-glycoprotein antibody JSB-1, revealed a 120-KDa protein, which was expressed, in high amounts on Cd2+-exposed cells (74% above the control values). Moreover, cells treated with JSB-1 became more sensitive to the harmful effects of cadmium, showing a decreased survival rate. Taken together, these results suggest that a MDR phenotype has evolved in Euglena as one of the mechanisms for cadmium detoxification.Abbreviations DTT dithiothreitol - mAb JSB-1 anti-human P-gp monoclonal antibody JSB-1 - MDR multidrug resistance - MRP MDR-associated protein - PBS phosphate buffered saline - P-gp P-glycoproteinCommunicated by G. HeldmaierA.J.F.O. and F.L.S.S. are undergraduate students under a CNPq special program for research training |
| |
Keywords: | Euglena gracilis Cadmium MDR P-glycoprotein Heavy metal |
本文献已被 PubMed SpringerLink 等数据库收录! |
|